The present invention concerns a procedure for the cross-linking of an ethylene copolymer and a polymerizable hydroxylated ester.
These copolymers of ethylene and of a hydroxylated ester, described for instance in U.S. Pat. No. 3,300,452, are of limited use because of the difficulty in cross-linking them. Although when these polymers are heated to temperatures between 170.degree. C. and 340.degree. C., their thermoplasticity is reduced and their tensile strength and their apparent molecular weight are increased, this high-temperature treatment, in any case very long, practically never leads to a complete cross-linking nor even a satisfactory one.